Locomotive crosshead



April 14, 1936- T. v. BUCKWALTER LOCOMOTIVE CROSSHEAD I 2 Sheets-Sheet 1 Filed April 28, 1933 #15 Hr ram/5K2 April 14, 1936. T. v. BUCKWALTER LOCOMOTIVE CROSSHEAD Filed April 23, 1933 2 Sheets-Sheet 2 '0/IIIIIIIIII/IIlllllllllllllfl -Patented Apr. 14; 1936 UNITED STATES PATENT OFFICE LOCOMOTIVE CROSSHEAD Tracy V. Buckwalter, Canton, Ohio, assignor to I The Timken Roller Bearing Company, Canton, Ohio, a corporation of Ohio Application April 28, 1933, Serial No. 668,336 voiaims. (cram-1'00) adjustment, inspection and removal and replace ,ment of the roller bearings; and to obtain other advantages hereinafter appearing. The invention consists in the crosshead and in the parts 15 and combinations and arrangements of parts hereinafter described and claimed. In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur, 20 Fig. 1 is a side elevation of a locomotive crosshead embodying my invention,

Fig. 2 is a horizontal longitudinal section on the line 2-2 in Fig.1, Fig. 3 is a vertical cross-section on the line 3-3 25 in Fig. 1,

Fig. 4 is a rear end view of the shoe member, Fig. 5 is a plan view of the yoke member, Fig. 6 is a front end view of said yoke member, Fig. 7 is a side elevation of a modified form of 30 crosshead,

Fig. 8 is' a horizontal longitudinal section on the line 8-4 in Fig. 7; and c Fig. 9 is a vertical cross-section on the line 9-9 in Fig. 'I.

" The present crosshead is particularly adapted for transmitting the reciprocating motion of the piston rod A of a locomotive to the front end of the main or connecting rod B thereof. The crosshead illustrated on sheet i ofthe drawings 40 comprises a yoke member C having a shank portion I adapted to be connected to the back end of the piston rod A and horizontally spaced par'allel branches 2 between which the forward end Q 55 portion of the wrist pin has a tight taper fit the opening in the main rod; and the ends of said wrist pin are rotatably supported in the openings in the respective branches 2 of the yoke'member. Thewrist pin is supported at its ends in antlfriction bearings, preferably tapered roller bearings 5 D, mounted in the branches of the yoke member. Each of the tapered rollerbearings D comprises a cone or inner bearing member 5, a conical cup or outer bearing member 6 and conical bearing rollers l interposed between said cone and cup. 10

The conical inner bearing members 5 are mounted on the ends of the wrist pin; and the conical outer bearing members 6 seat within the openings in thebranches of the yoke member.

The yoke member C is suspended from a guide member E for sliding movement parallel to the axis of the piston rod A by means of a shoe F. The guide member E, which is rigidly secured, to the locomotive. in any desired manner (not shown), is of substantially inverted channelshaped cross-section with vertically spaced outstanding fianges along its side walls that form ways or slides 8 in which the shoe F moves. The shoe F comprises a portion 9, which is provided along its opposite sides with vertically spaced outstanding flanges 9a. that slidably engage the ways 8 in the guide E, and a rearwardly opening hookshaped portion ID that fits between the branches 2 of the yoke member C and loosely embraces the forward end of the main rod B so as to permit the necessary angular movement thereof. The depending hook portion to of the shoe F is rigidly secured betweenthe branches of the yoke member of the crosshead by a series of annularly spaced through bolts II that extend through 3 registering horizontal openings provided therefor in said branches and said hook portion.

The cups or outer bearing members 6 .of the tapered roller bearings D are held in the openings provided therefor in the branches 2 of the yoke 40 member by means of annular plates I2 that are secured to the outer faces of said branches with their inner margins overlapping the outer ends of said outer bearing members 6. Adjustment of the outer bearing members 6 to take up wear in the bearings is accomplished preferably by means of thin shims I3 interposed between the annular plates 12 and the branches 3 of the yoke member. As shown in the drawings, the annular retaining members i2 are held in placeat points opposite the yoke engaging portion of the shoe F by means ofthe securing bolts l l andat points intermediate said bolts by means of cap screws Ila. The wrist pin 3 is held against endwise movement in one ldilfgctionby reason of its tapered fit in the main the cone or inner bearing member 6 of the adjacent roller bearing.

As shown in the drawings, the outer bearing member 6 of each roller bearing is provided at the ends of its conical raceway with annular flanges or thrust ribs l that loosely confine the bearing rollers 1 therebetween. The usual cage is dispensed with and a full circular series of bearing rollers 'I is used, a proper running flt being provided for said rollers. Only a slight clearance is provided between the thrust ribs or flanges l5 of the outer bearing member 6 and the inner bearing member 6, so that in the event that the bearing rollers 'are flattened under very heavy loads or shocks, said flanges will come into contact with the cylindrical end portions of said inner bearing member, thus producing a plain bearing that cooperates with the roller bearing.

The wrist pin 3 is made hollow so as to provide a chamber or reservoir 16 for lubricant. The outer end of the hollow wrist pin is closed by means of, a closure member in the form of a plug I7,- which has an oil feed fitting l'la therein and is held tightly in said end of said pin by means of a ring nut l8 threaded thereon. Said ring'nut is provided with diametrically opposed notches l9 adapted to receive the'ends of a locking pin 20 which extends through perforated lugs 2| provided therefor on the plug H. The other or inner end of the hollow wrist pin 3 is closed by means of a plug 22 that is held in position by means of a pin 23 that is supported in perforated lugs 24 on said plug with its ends fitting in diametrically opposed notches 25 provided therefor in the ring nut I 4 that is threaded on the inner end of said wrist pin in abutting relation to the cone 5 of the supporting bearing therefor. The wrist pin 3 is provided adjacent to the small end of the cone 5 of each tapered roller bearing D with a plurality of radial extending holes 26, whose outer ends communicate with an annular groove 21 around the inner periphery of said cone. Said cone is provided with radial lubricant passageways 26 leading from the annular groove 21 in said cone to the outer end of the raceway thereon. With this arrangement, the movement of the wristpin 3 causes the lubricant therein to pass out through its radial passageways 26 into the annular groove 21 and thence through the radial passageways 28 into the space occupied by the bearing rollers I.

Mounted on the outer end of the wrist pin 3, between the ring nut l8 and a shoulder 29 on said wrist pin is an arm 30 that serves to transmit the motion of the sliding crosshead to the valve gear (not shown) for controlling admission to and exhaust of steam from the locomotive cylinder. A plain bearing sleeve 3| is interposed between the wrist pin and the valve gear operating arm 30 to cut down friction therebetween.

Figs. 7, 8 and 9 illustrate a pivoted crosshead construction. In this construction, the yoke C is formed integral with the back end of the piston rod B and'has its branches 32 formed with outstanding pivot bosses 33 that surround the bearing receiving openings in said branches and are rotatably supported in openings 34 provided therefor in spaced parallel plates 35 that depend from the underside of a slidably supported shoe F The depending yoke supporting plates 35 of the shoe F are bolted or otherwise removably secured by bolts 36 to the outer faces of spaced parallel flanges 31 that depend from the underside of said shoe. Bronze liners 39 are interposed between the bosses 33 of the branches 32 of the yoke C and the openings in the plates 35 that depend from the shoe or slipper F The wrist pin 40, which pivotally connects the main rod A to the yoke C is supported in the openings in the branches 33 of said yoke by means of taper roller bearings D whose inner raceways are formed on the wrist pin itself. The bearings D are held in place in the branches of the yoke by means of annular plates 4| that are secured by bolts 42 to the outer faces of the pivot bosses 33 in overlapping relation to the outer raceway members of said bearings. The bearings are adjusted by means of shims 43 interposed between the annular plates and the pivot bosses.

The hereinbefore described crosshead has numerous advantages. The separation of the crosshead into two parts, the shoe F and the yoke C,

permits the selection of proper material 'for these parts. For instance, the yoke maybe made of forged steel or other alloy, while the shoe may be made in the form of a casting of relatively cheap metal. This making of the crosshead in two parts also reduces the weight thereof and facilitates assembly of the roller bearings; These roller bearings serve, not only to reduce friction between the parts and thus prolong the life thereof, but they also enable a further reduction in weight to be obtained by dispensing with the use of heavy brasses, wedges, adjusting devices and locking means. the temperature of the parts when running and permit the use of light weight material, such as aluminum alloys, in the main rods. The reduced weight of the reciprocating parts also permits the use of a smaller wrist pin. The wrist pin is made hollow and thus constitutes a reservoir for lubricant which is metered to the bearings where it is trapped by the thrust flanges l 5 of bearing cups 6 and the close fitting b'earing rollers I. The bearing rollers are adjustably held in place by the rings l2 that are secured to the branches of the crosshead by the cap screws Ila and the through bolts II, which bolts serve to hold the yoke and shoe firmly together and also to prevent the branches of the yoke from spreading.

The pivoted. crosshead construction has all The roller bearings also reduce,

of the advantages of the rigid type of crosshead and the additional important advantage that it permits relative pivotal movement as between the yoke and the slidable shoe and thus prevents bending or bowing of the piston rod or tilting and jambing of the shoe in its guide due to the inertia of the reciprocating parts.

Obviously, the hereinbefore described crosshead construction admits of considerable modification without departing from the invention.

Therefore,'I do not wish to be limited to the precise construction shown.

What I claim is:

1. A crosshead comprising a yoke having alined openingsin its branches, at wrist pin extending crosswise of said branches .with its ends extend-- ing spaced branches, 8.

aosaaoa I ing into openings therein, a shoe havin a portion that extends between said branches clear said wrist pin, roller bearings for supporting the ends of said wrist pin in said opening rinw on-the outer .iaces of said branches --and overlapping the bearin'gs therein, and bolts for securing said rings to said branches and-for securing said shoe therebetween.

3. A cro'sshead comprising a yoke member having spaced branches, a'. wrist pin extending crouwise of'said branches with its ends iournaled therein, a shoe having a portion extending between said branches that, extends partway around said wrist pin and is spaced therefrom,

and bolts for removably securing to said branches the portion of the 4. A crosshead comprising a yoke member havwrist pin extending crosswise of said branches, a shoe having a portion extending between said branches'that extendsv partway around said wrist pin and is spaced therefrom, roller bearings mounted in said branches for rotatably supporting the ends of said wrist pin therein, bolts for removably securing to said branches the portion of the shoe extending therebetween, and rings overlapping the outer ends of said bearings and partially held in place by said bolts.

5. A crosshead comprising a yoke member having spaced branches, a wrist pin extending crosswise or said branches with its ends therein, and a shoe having a portion disposed behoe extending therebetween. v

journaied tween and removabiy secured to said branches,

said portion extending downwardly between said branches and beneath said wrist pin.

6. A locomotive crosshead construction com! prising a reciprocating yoke member having spaced branches, a wrist pin disposed transversely oisaid branches, taper roller bearings mounted in said branches for rotatably supporting said wrist pin therein, each of said bearings comprising anouter bearing member and rollers between said outer bearing member and said wrist pin,

and means for removably securing said bearings in said branches, said means comprising annular members bolted to said branches and overlapping the outer ends of the outer bearing members.

'1. A'crosshead construction comprising a yoke -member having spaced branches, a wrist pin dis posed transversely oi said branches, taper roller bearings mounted in said branches for rotatably sipporting said wrist pin therein, each oi said bearings comprising an outer bearing member and rollers between said outer bearing member and said wrist pin, means for removably securing said bearings in said branches, said means comprising annular members bolted to said branches and overlapping the outer ends of the outer bearing members, and adjusting shims in- .terposed between said annular members and said branches.

TRACY V. BUCKWALTER. 

